Canon EF 24-70mm f/4L IS USM Instructions Manual page 12

7. Exposure during Close-up Shooting
Setting the Exposure
When taking photographs using TTL metering,
no exposure compensation is necessary to
meter the light coming through the lens.
With TTL metering, AE (autoexposure) is
possible at all focusing distances. Just set the
desired picture-taking mode, then check the
shutter speed and aperture before taking the
picture.
Magnification and Effective
f-number
The aperture displayed by the camera assumes
that the focus is set to infinity. The actual
aperture (effective f-number) becomes darker
(effective f-number increases) at closer focusing
distances (magnification increases). This does
not cause exposure problems for normal picture-
taking. However, for closeup photography,
you cannot ignore the change in the effective
f-number.
When you use a handheld exposure meter to
set the exposure, you must take into account the
exposure factor shown in the following table.
Magnification 1 : 5
Effective f/No. 4.71
+1/3
Exposure Factor
(stops)*
+1/2
* Upper values: 1/3 stops. Lower values: 1/2 stops.
The correct exposure for a close-up shot largely
● ●
depends on the subject. Therefore, try to bracket
the exposure for the same subject.
Using aperture-priority AE (Av) or Manual (M)
● ●
picture-taking modes are recommended for
macro photography as it is easy to adjust depth
of field and exposure in these modes.
1 : 3 1 : 2 1 : 1.5
5.06 5.66 5.66
+2/3 +1 +1
+1/2 +1 +1
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